What is the purpose of the \'

Understanding the PHP Heredoc Syntax: What does "<<<" Represent?

In PHP, the "<<<" syntax is used to create a heredoc string. Here's how it works:

Starting a Heredoc String

To initiate a heredoc string, use the following syntax:

<<<HEREDOC_TOKEN

where HEREDOC_TOKEN can be any word or phrase.

Example:

$sql = <<<MySQL_QUERY

Ending a Heredoc String

To terminate the heredoc string, simply place the HEREDOC_TOKEN on a new line, followed by nothing else:

HEREDOC_TOKEN

As an exception, you can optionally include a single semicolon after the end token.

Preserving Newlines and Content

The heredoc syntax allows you to create multiline strings with preserved newlines and other content. This can be useful for generating SQL queries, HTML templates, or other text-based outputs.

Example

The following code uses a heredoc string to generate an HTML header:

echo <<




Welcome to my site!


HEREDOC;
Note: The HEREDOC_TOKEN used in the heredoc string must be unique and should not appear elsewhere in the string, as this will cause a syntax error.
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